1. Field of the Invention
This invention relates to a chain drive assembly, and more particularly to a silent chain for transmitting a drive power from a fluid type torque converter of an automatic transmission to an auxiliary transmission.
2. Description of the Prior Art
A drive power transmitting mechanism incorporating a silent chain has suffered from noise during transmission of a drive power, which noise is principally caused by two factors: one is an elastic vibration sound resulting from a shock upon meshing of a chain with sprockets (a sound of meshing); and the other is a resonant sound developed as a result that a shock upon meshing of a chain with sprockets is increased by oscillation of the chain stringer. The first factor may be eliminated by correcting a sprocket tooth configuration properly to lower a shock upon meshing between the chain and sprockets. In order to eliminate oscillation of the chain stringer which constitutes the second factor, it is effective to use an anti-oscillation member, such as a tension member or a chain guide. However, such anti-oscillation member requires a considerable space for installation, needs fine adjustment of a gap between the member and the chain, suffers wear and the accompanied dust or the like which would impose an undesirable influence on other functional portions of a chain drive assembly, and is costly to manufacture.
As other countermeasures against the second factor, a system has been proposed, of eliminating a clearance between link plates, so as to provide a resistance to the bending movement of the chain, thereby preventing oscillation of the chain stringer. With such a system, an increase in component is avoided unlike the case where an anti-oscillation member is employed, and yet, a resistance to the bending movement of the chain largely changes even by a small difference in thickness between link plates, and by swelling. Such a system has accordingly failed to provide a proper and constant bending-resistance value, and suffered from the accommodation of one link plate to the other and accelerated wear during the service of the chain, which would lead to a lowered frictional resistance and eventually make the system useless.